The objectionable part is the magnitude, not the subject matter.
It's just named differently and adds more paperwork (more performance warnings, "talks" with your manager, etc.) before you get terminated.
I can't speak for other companies but I work at Google and I've met several people over the years who've confided with me that they've been on PIP (either in the past or at the moment when talking to me). While (thankfully) I haven't been on PIP myself (yet!) so I can't speak from personal direct experience, I can confidently say that all the people I know personally that were on PIP have successfully re-focused their career, haven't gotten fired, and are still working at the company years later.
Obviously it might be survivorship bias and I might simply not be meeting those that do not succeed, but at least I can confidently say that being put on PIP itself is not necessarily just an excuse to get you fired.
I think we generally do not hear about the cases where a PIP was used and the employee was genuinely not meeting expectations, or when a PIP was used and the employee course corrected and went on to have a successful career.
My manager either wanted me to start doing my job again, or leave and create a space on the team for someone who would. He seemed slightly biased in favor of keeping me on the team. It didn't seem like a fun situation for him to deal with at all.
I ended up leaving, but it's because I was disengaged and didn't see a way out of it. (And I had great offers elsewhere.) Not because my manager was being abusive.